PCMCIA slot not working on Dell Latitude E5520 laptop

At my job we purchased from Dell website for Spain (http://dell.es) three identical Dell Latitude E5520 laptops, and in none of them the PCMCIA slot works. The failure varies from a complete freeze when introducing a PCMCIA card, to card not being recognized, depending on the laptop and card.

We tested eight different types of PCMCIA card:

Compact flash to PCMCIA adaptor (with any CF card).

5 in 1 card reader.

Serial port.

Parallel port.

Ovislink RJ45 10/100 ethernet.

Modem 56K.

Ecom wifi.

Allen-Bradley communication card 1784-PCMK.

Since at work we use heavily this last very expensive (much more than the laptop itself) PCMCIA Allen-Bradley communication card, we thought this laptop would fully fulfill our needs. On the contrary, if this card doesn't work the laptop is as useless as a brick for us.

All above mentioned PCMCIA's are old tested cards, all working in other laptops (Toshiba, Clevo, HP, another four years old Dell, etc).

And it is not a matter of these just three laptops manufactured at the same time: in the third repair attempt (see below) by Dell of one of the laptops the motherboard was substituted. The motherboard was probably not manufactured at the same time as the laptops, and, being a refurbished motherboard, it was supposed to be tested.

Also, it is not an operating system issue (Windows 7 32 bits, but see below). Booting in Linux (pendrive or live CD) error messages are generated when inserting or removing cards ('dmesg'). Also, on this post: http://groups.google.com/group/comedi_list/browse_thread/thread/04ed51e0772e2fe3/7749503d789dff2b?show_docid=7749503d789dff2b&pli=1 he is working in Linux with an expensive specialized measurement PCMCIA NI-DAQ 6024e by National Instruments, and has problems.

Repair attempts by Dell, having started with one of the three deffective Dell Latitude E5520 laptops more than one month ago:

Same deffective Dell Latitude E5520 laptop sent to wherever. OS changed from Windows 7 32 bits to Windows 7 64 bits. Problem remained. Obviously, they didn't test, although we included, as suggested by Dell support for Spain (in Romania), three PCMCIA cards for test. And worse, Windows 7 64 bits turned the laptop into a complete brick for us, since we use some specialized licensed programs which run only in Windows 32 bits. Obviously, they also deleted our information, installed programs, updates, etc. There was no reason to change the OS (it was a hardware problem) and problems remained.

A repairman sent by Dell came to the office to substitute the motherboard in above same deffective Dell Latitude E5520 laptop. The motherboard version had the same version and bios, but it was a refurbished one, which could be a good hope. Problem remained. Obviously, even if the motherboard was a refurbished one, it had not been tested. The repairman told us that in ten years working with Dell and other laptop manufacturers he hadn't seen anything like this.

This is a hardware problem (not OS), and it can be a bad batch of components, a laptop design error, or some chip design error. But worse, it shows that Dell doesn't test the laptops they sell, and does not test refurbished motherboards meant for repairs. And yet worse, if it is a chip design error it can appear not only in other Dell laptops, but even in others from other manufacturers using the same chip.

Another consideration: above mentioned old Dell laptop (Latitude D520) in which the PCMCIA's work was made in Ireland, and has always worked beautifully. These deffective Dell Latitude E5520 laptops are made in China. Not only they are deffective: obviously they have not been tested. Does this happen with other chinese Dell laptops?

And, what does Dell Service for Spain (in Romania) do? Incredibly, since the laptop has been tried to repair three times without success, we must accept that the laptop has this deffect. No matter how many times I call them, no matter how many times I talk with a supervisor, that is the answer. Not accepting this (we need the PCMCIA slot as appears above) they say they will call us later and never call, and this happens day after day.

I have no contact above Dell Service for Spain (in Romania) to complain or just to communicate the problem. They just ignore us.

I thought that Dell guaranteed their products against any manufacturing deffect, but this does not seem the case. What warranty is "accept the deffect"? The manual for this Dell Latitude E5520 is http://support.dell.com/support/edocs/systems/late5520/en/SM_EN/index.html. The PCMCIA slot appears there. Well, really it does not say it works, so it must be decorative.

So people reading this and having recent Dell Latitude E5520 laptops with PCMCIA or ExpressCard should test this slot. The simplest test for PCMCIA is a PCMCIA to Compact Flash card adapter with a Compact Flash card inserted; this adaptor is only mechanical (connects the 50 CF card pins to some of the 68 PCMCIA bus pins) and very cheap. When inserting it, after a while, the CF card should be recognized and should appear in Windows as a new drive unit.

Above is a comparison of what appears in a deffective Dell Latitude E5520 laptop with Windows 7, and the same in a Clevo with XP. But note that it is not an operating system problem (appears also with Linux).

People reading this can post their experience, good or bad. It would also help if someone posts his PCMCIA slot really working.

Since there
have appeared posts in other phorums asking if this card Allen-Bradley
communication card 1784-PCMK is supported in Windows 7 here I include screen
captures (on laptop named E5520-L above) on it, showing its resources and
driver:(incluir
E5520-L_1784_PCMK.png)

This refers to the Allen-Bradley communication card 1784-PCMK, working in one
of our three deffective Dell Latitude E5520 recently purchased (may
2011) laptops, named E5520-L above. Some people have asked if this card was
supported in Windows 7. I had to leave, so I had no time to include figure
E5520-L_1784_PCMK.png, which includes screen captures on this board, showing its
resources and driver. Note driver date (january 25 2010). Here it goes:

When describing resources on a XP SP3 laptop with two PCMCIA slots and
a PC
CARD and a Cardbus cards inserted:

Compact Flash adaptor (with a CF card);

Parallel port (Moschip);

I
wrote:

They
appear as a PCMCIA IDE/ATAPI controller (with ISA IRQ4) and a PCI Parallel Por (LPT3) (with PCI
IRQ10), and also coexist peacefully. IRQ10 is shared by a lot of
devices.

IRQ4 should be IRQ7, as appears in the figure. ISA IRQ4 is occupied by COM1
communication port, and cannot be shared.

SpeedStep says:

I
have no Idea what VISTA or Windows 7 does but I suspect that the 16 BIT DOS ISA
IRQ's are not supported.

On
above tests
of PC Card cards and Cardbus cards using a PCMCIA to PCI adapter based on a
Ricoh RL5C475A chip inserted in a modern desktop with Windows 7 64 bits, low
numbered IRQ's are indicated as ISA. When the 56k modem PC Card card is
inserted, its IRQ is numbered as 0x10 (16), one unit above classical ISA interrupts (0-15). Go figure.

All I can say is that it worked perfectly (see above Teraterm session).

While above posts were written, on july 28 2011 Dell released a new bios for the Dell Latitude E5520 (version A02). On its features nothing is said about its PCMCIA slot problems, but it seems that this bios A02 solves them.

Resources for following cards:

Allen-Bradley communication card 1784-PCMK (Cardbus),

Parallel port (Moschip) (Cardbus),

Serial port (Oxford Semiconductor) (Cardbus),

Compact Flash adaptor (with a CF card) (PC Card).,

USB 2.0 adapter (NEC) (Cardbus),

follow:

We have succesfully upgraded to bios A02 two of the three laptops (named E5520-L and E5520-N above) and PCMCIA cards work satisfactorily, with resources shown above. Third laptop (named E5520-M above), which froze when inserting any Cardbus card, will be tested in two weeks.

No one from Dell Service for Spain (in Romania), after one and a half month since problem was detected (mid june), told us to wait for a next coming bios. In adition, someone, graciously illuminated, for solving a bios problem, as we had anticipated, substituted in named above E5520-N Dell Latitude E5520 its Windows 7 32 bits operating system for the 64 bits one, deleting our long Windows upgrades, our installed programs and our documents, and leaving the laptop as usefull as a brick for us, since we use some industrial software which needs 32 bits Windows.

So people owning a Dell Latitude E5520 laptop should upgrade its bios to version A02. Finally, it is an excellent laptop, with an excellent screen (we purchased the one with 1920x1080 screen).

A Personal Computer Memory Card International Association (PCMCIA)
device that works correctly in Microsoft Windows 98, Microsoft Windows
98 Second Edition, Microsoft Windows Millennium Edition, and Microsoft
Windows 2000, may not work correctly in Windows XP. If this problem
occurs, a black exclamation point (!) on a yellow field is displayed on
the device in Device Manager. Additionally, no resources will be
allocated to the device.

As Far As I can tell Cardbus is gone. This is due to the Chipsets for motherboards being express card/PCI-E vs CardBus/AGP

If the operating system routes an interrupt from a 16-bit PC Card
that does not support shareable PCI interrupts, then the system might
stop working. To prevent this from happening, you should indicate that
the card does not support shareable interrupts by placing a PcmciaExclusiveIrq directive in the card's INF file.

For example, assume you have a modem whose driver contains an
interrupt service routine (ISR) that was not designed to support
interrupt sharing. You can direct the operating system to assign a fixed
ISA interrupt to the modem by adding the following line to an AddReg section in the modem's INF file:

HKR,,PcmciaExclusiveIrq,0x00010001,1

Note, however, that once you put the PcmciaExclusiveIrq
directive in a device's INF file, the device will not function with any
controller or bridge that does not have access to ISA interrupt.

There are problems related to 16-bit PC Card devices that
require ISA interrupts to operate and why vendors should move to
support shareable PCI interrupts. It also explains how device vendors
with devices or drivers that do not support sharable PCI can inform
Microsoft Windows operating systems using an INF.

The article also
introduces Microsoft plans to require that 16-bit PC Card devices and
drivers support shareable PCI interrupts in order to receive the
"Designed for Windows" logo.

Introduction

16-bit
PC Card devices that require ISA interrupts cause significant problems
for end users because, in some systems, CardBus controllers do not have
an ISA interrupt connected to them. Therefore, such CardBus controllers
cannot provide an ISA interrupt to devices inserted into CardBus slots.
If a device appears that requires an ISA interrupt (which is relatively
common for 16-bit PC Cards), the device cannot function and may cause
system-wide problems, such as interrupt storms.

This article
explains this problem in detail. The long-term solution to this problem
is to implement a proposed new logo requirement that would require all
16-bit PC Card devices to support shareable PCI interrupts.

Note:
Before the advent of CardBus, 16-bit PC Cards were connected to the
system over a legacy PCMCIA bridge (also referred to as a PCIC bridge).
These bridges are not capable of running CardBus cards or routing 16-bit
PC Card devices to a PCI IRQ. The information in this article about
routing to PCI interrupts does not apply to PCIC bridges.

Types of PCMCIA Devices

There are two classes of PCMCIA cards, both of which are supported by CardBus controllers:

32-bit PCI-compliant CardBus PC Cards. In this document, these devices are referred to simply as "CardBus cards."

16-bit PC Cards, which are essentially ISA devices.

Interrupt Routing for CardBus and 16-bit PC Cards

CardBus
cards are essentially PCI devices, and their interrupts are routed to
PCI IRQs as defined by the PCI specification. 16-bit PC Cards were
defined before the advent of PCI, and their interrupts were, therefore,
typically routed to ISA IRQs. It is important to note that 16-bit PC
Cards can also support routing interrupts to PCI. However, they have to
meet the following two basic requirements in order to successfully use
PCI interrupts instead of ISA interrupts.

Support PCI level-triggered interrupt generation.
Most 16-bit PC Cards support level-triggered interrupts because the
support is defined in the PCMCIA specification and because CardBus
controllers have the ability to route 16-bit PC Card interrupts either
to an ISA IRQ or to a PCI IRQ.

Support interrupt sharing.
PCI interrupts are shareable. Therefore, 16-bit PC Cards and their
drivers must be designed to handle interrupt sharing. Many 16-bit PC
Card drivers do not successfully support interrupt sharing. Common
problems that prevent devices and drivers from sharing interrupts are:

The
Interrupt Service Routine (ISR) in the driver for the card was not
designed to return the proper indication that a given IRQ was generated
by its respective device. This is one of the primary prerequisites for
correct ISR operation.

The card does not correctly
provide an indication in hardware registers that it is asserting an IRQ,
thus denying the ISR the ability to function correctly on a shared IRQ.

The card generates a spurious interrupt on power up.

All of these problems cause an interrupt storm, which will cause the system to stop responding.

System Configuration Issues

Although
many 16-bit PC Card drivers do not successfully support interrupt
sharing (and therefore require an ISA interrupt), there are system
configurations on the market in which the CardBus controller is not
connected to any ISA IRQ, and therefore, cannot provide an ISA interrupt
to 16-bit PC Cards.

Examples of configurations where CardBus controllers do not have a connection to an ISA interrupt include:

A
desktop machine with a CardBus controller plugged into a standard PCI
slot. In this case, the CardBus controller does not have access to an
ISA interrupt, because ISA interrupts are never present at a PCI slot.
In the past, these PCI cards may have been distributed with an ISA
"paddle card." The purpose of the paddle card was to provide a
connection to ISA IRQs. However, paddle cards are typically no longer
available.

A Mini-PCI device that contains an R2 PC Card
device installed behind a CardBus controller. These are typically
wireless devices.

Because no ISA interrupts are
available for CardBus controllers in these configurations, PCI
interrupts are the only type of interrupts available. However, if a
device that does not support PCI interrupts is inserted into a CardBus
slot in this system, it will not function and may cause system-wide
problems, such as an interrupt storm.

Ideally, no device would
require an ISA interrupt, and Windows could just assign shareable PCI
interrupts to all 16-bit PC Cards. Microsoft is planning to require
support for PCI interrupts in future versions of the "Designed for
Windows" Logo requirements so that this problem can be avoided.

INF Overrides

If
Windows routes an interrupt from a 16-bit PC Card and that card does
not support shareable PCI interrupts, then the system may stop
responding. To avoid this problem, vendors should always support
shareable PCI interrupts. If a device does not support shareable PCI
interrupts, it should inform Windows using this INF override so that an
interrupt storm can be avoided.

PcmciaExclusiveIrq:This
setting can be specified in the INF of the target device to prevent
Pcmcia.sys from routing that device to a shared IRQ. For example, if the
a modem fails to support interrupt sharing because its drivers ISR was
not designed for it, the following directive can be specified in its INF
(in an AddReg section):

HKR,,PcmciaExclusiveIrq,0x00010001,1

CAUTION:
This INF setting effectively breaks this device for all bridges that
have no ISA IRQs detached. Use this setting only when it is absolutely
certain that the device cannot function on a shared PCI IRQ.

Logo Requirement Timeline

As
stated earlier in this article, future planned logo requirements will
require all 16-bit PC Card devices to support shareable PCI interrupts.
This is a proposed logo requirement and will take effect 18 months after
the formal requirement is published.

Note to 16-bit PC Card vendors:
In the same timeline, your devices will be required to support flexible
allocation of I/O resources for your devices. That is, 16-bit PC Card
devices will not be allowed to request specific ranges of I/O space, but
will only be allowed to request a specific amount of I/O space.

Resources and Call to Action

Call to Action:

System
manufactures should be aware that there are devices that require ISA
IRQs. Therefore, system vendors should ensure that ISA IRQs are
available to CardBus controllers in the system until the logo
requirements described in this article help phase out this problem.

Device manufacturers should
implement CardBus devices instead of 16-bit PC Card devices because
they are PCI compliant and not legacy ISA.

If a vendor
must implement 16-bit PC Card devices, design them to support shareable
PCI interrupts. R2 cards that support PCI shared interrupts are much
more likely to work properly because they do not rely on system
manufacturers to wire an ISA interrupt to the CardBus controller.

Driver developers should design drivers to support shareable PCI interrupts.

Your posts refer in general to 2000 and XP; nothing is specific to Windows 7. I will group the PCMCIA cards we tested in our E5520 laptops (plus a new one: an USB 2.0 adapter) in a different way:

PC Card cards:

Compact Flash adaptor (with any CF card).

5 in 1 card reader (with a SD card).

Modem 56K.

Cardbus cards:

Serial port (Oxford Semiconductor).

Parallel port (Moschip).

Ovislink RJ45 10/100 ethernet (Linksys).

Ecom wifi.

USB 2.0 adapter (NEC).

Allen-Bradley communication card 1784-PCMK.

According to what appears above, for the moment I will not consider PC Card cards. In my initial post appeared:

"...we purchased ... three identical Dell Latitude E5520 laptops, and in none of them the PCMCIA slot works. The failure varies from a complete freeze when introducing a PCMCIA card, to card not being recognized, depending on the laptop and card..."

None of the three laptops recognize the PC Card cards.

I didn't want to make the post too long but what really happens is that the three Dell Latitude E5520's work differently. In all that follows I'll call them E5520-L, E5520-M and E5520-N (they have very similar service tags, differing only in one letter L, M and N). This is what happens:

E5520-L: parallel port, usb adapter and Allen-Bradley cards work; the other three show resource problems.

E5520-M: freezes when inserting any Cardbus card (this also happened in E5520-N before first repair attempt by Dell (PCMCIA cage substitution)).

E5520-N: parallel port and usb adapter cards work; the other four show resource problems.

All above mentioned Cardbus cards work in every other laptop I have tested apart from our three Dell Latitude E5520's (other Dell made in Ireland, Clevo, HP, Toshiba, etc). If some work and others not in our three Dell Latitude E5520's the conclusion is that the PCMCIA slot on Dell Latitude E5520 laptop does not work; possibly, according to this:

E5520-N: it froze before first repair (PCMCIA cage substitution) when inserting the Allen-Bradley communication card 1784-PCMK (and any Cardbus card). After this repair, it shows resources problem when inserting the Allen-Bradley communication card 1784-PCMK.

We have no idea of why this three different behaviours of the Allen-Bradley communication card 1784-PCMK in our three Dell Latitude E5520's, but this shows that there is certainly a problem with the PCMCIA slot on the Dell Latitude E5520.

"Low voltage CPU's mean that 32 BIT 3.3V cardbus is all that is still supported"

I agree, but as a conclusion all cardbus cards should work on the Dell Latitude E5520, and not a few; in other words, we have no idea of which cardbus card will work and which won't. In adition, why a particular card (Allen-Bradley communication card 1784-PCMK) shows three different behaviours?:

The PCMCIA association was disolved in 2009; www.pcmcia.org doesn't exist. The Wikipedia is a very good source of information for PCMCIA issues. Information about ExpressCard cards can be found in http://expresscard.org.

This and other mentions on your post are helpful for making PC Card and Cardbus cards work in XP. From what I have seen XP (and possibly 2000) support perfectly PC Card and Cardbus cards, even in strange situations. They may require registry adjustments, as you say. Some examples follow, taken from a laptop with XP SP3 with two PCMCIA slots controlled by a Texas Instruments PCI-1520 cardbus controller chip.

Above two PC CARD cards are inserted:

Compact Flash adaptor (with a CF card).

5 in 1 card reader (with a SD card).

Both appear as a PCMCIA IDE/ATAPI controllers, which coexist peacefully. One gets assigned ISA IRQ4 and the other ISA IRQ7.

Above two PC CARD cards are inserted:

Compact Flash adaptor (with a CF card).

Modem 56K.

They appear as a PCMCIA IDE/ATAPI controller (with ISA IRQ4) and a KORTEX 56000 PCMCIA Card (with ISA IRQ7), and also coexist peacefully.

Above a PC CARD and a Cardbus cards are inserted:

Compact Flash adaptor (with a CF card).

Parallel port (Moschip).

They appear as a PCMCIA IDE/ATAPI controller (with ISA IRQ4) and a PCI Parallel Por (LPT3) (with PCI IRQ10), and also coexist peacefully. IRQ10 is shared by a lot of devices.

See also that when a PC Card card is inserted its resources appear out of the resources ranges belonging to the Texas Instruments PCI-1520 cardbus controller chip. When a Cardbus card is inserted its resources appear within the resources ranges belonging to the Texas Instruments PCI-1520 cardbus controller chip.

So all this, and what is mentioned in your post, shows that XP supports very well PC Card and Cardbus cards. But, what about Windows 7?

The only laptops with Windows 7 and a PCMCIA slot I have at hand are our deffective Dell Latitude E5520 laptops. Since some Cardbus cards work, it is clear that Cardbus cards are supported by Windows 7. For other tests of PC Card cards and Cardbus cards I inserted a PCMCIA to PCI adapter based on a Ricoh RL5C475A chip in a modern desktop with Windows 7 64 bits. Captures of three PC Card cards and three Cardbus cards follow.

PC Card cards tested:

Compact Flash to PCMCIA adaptor (with a CF card).

5 in 1 Card Reader (with a SD card).

Modem 56K.

Cardbus cards tested:

Parallel port (Moschip).

USB 2.0 adapter (NEC).

Serial port (Oxford Semiconductor).

PC Card cards.

Compact Flash to PCMCIA adaptor (with a CF card) PC card card.

5 in 1 Card Reader (with a SD card) PC card card.

Essentially, the Compact Flash to PCMCIA adaptor (with a CF card) and the 5 in 1 Card Reader (with a SD card) appear the same (as a PCMCIA IDE/ATAPI controller) and use the same resources.

Resources shown. Note that also appears a NEC USB 3.0 controller located in the motherboard.

Serial port (Oxford Semiconductor) Cardbus card.

Resources shown.

Somebody may argue that since interrupts from the PC Card cards go through a PCI connector ISA problems mentioned before cannot appear. The answer is: that could also be done inside the Dell Latitude E5520 laptop electronics.

In above other tests of PC Card cards and Cardbus cards using a PCMCIA to PCI adapter based on a Ricoh RL5C475A chip in a modern desktop with Windows 7 64 bits one thing was clear: all cards (PC Card and Cardbus cards) were installed easily and accepted their drivers easily (even in Windows 7 64 bits), very different to what is happening with our three deffective made in China Dell Latitude E5520 recently (may 2011) purchased laptops.

"As Far As I can tell Cardbus is gone. This is due to the Chipsets for motherboards being express card/PCI-E vs CardBus/AGP"

Wouldn't it better to say Cardbus/PCI than Cardbus/AGP?

Yes, Cardbus is gone; it is substituted with ExpressCard. See what appears above about NI Cardbus cards. Newer laptops appear with a ExpressCard slot. But we looked for a laptop with PCMCIA slot, and Dell offered it in the Dell Latitude E5520, and we hoped it would work. This has not been the case, and we are extremely angry and dissappointed. The three repair attempts by Dell have been useless, and more: Dell service for Spain has substituted without any reason the Windows 7 32 bits operating system in one laptop for the 64 bits one, which not only is useless for us (we use some industrial software which needs 32 bits Windows): they deleted our long Windows upgrades, our installed programs and our documents. This laptop is as usefull as a brick for us now, and Dell service for Spain (in Romania), not only doesn't help at all about the PCMCIA problem (they tell us to accept the laptop with this deffect), but also doesn't respond about the operating system substitution, no matter how many times we call them.

"If the operating system routes an interrupt from a 16-bit PC Card that does not support shareable PCI interrupts, then the system might stop working..."

But all above discussions refer to XP, with dates up to 2007, therefore before Windows 7 era, and without any mention about applying or not to Windows 7. Our complaints about the three deffective Dell Latitude E5520 purchased laptops refer specifically to the fact that problems also appear booting in Linux (pendrive or live CD): error messages are generated when inserting or removing cards, as can be seen with the 'dmesg' command. It is a bios problem, hardware problem or design error, and remember that the three deffective Dell Latitude E5520 purchased laptops behave differently with the Allen-Bradley communication card 1784-PCMK:

E5520-L: works.

E5520-M: freezes.

E5520-N: resources problem.

Recall also that these three deffective Dell Latitude E5520 purchased laptops have been made in China; the old Dell in which all tested PCMCIA cards (PC Card and Cardbus type) work without any problem was made in Ireland.

CONSIDERATIONS AS SIMPLE USER

If thinking as a common user, follows the information we had about the Dell Latitude E5520:

From our offer from Dell for three Dell Latitude E5520 laptops, dated may 6 2011:On that image I would like to point out:

212-10373 Base Option : PCMCIA card base. How can anyone imagine it was not going to work?

619-26317 Operating System : Spanish Genuine Windows 7 Professional (32Bit OS). The three deffective Dell Latitude E5520 purchased laptops were supplied with this operating system, but on the second PCMCIA repair attempt by Dell on one of them (previously named E5520-N) it was substituted without any reason for the 64 bits one, which not only is useless for us (we use some industrial software which needs 32 bits Windows): they deleted our long Windows upgrades, our installed programs and our documents. This laptop is as usefull as a brick for us now, and Dell service for Spain (in Romania), not only doesn't help at all about the PCMCIA problem (they tell us to accept the laptop with this deffect), but also doesn't respond about the operating system substitution, no matter how many times we call them.

CONSIDERATIONS AS ADVANCED USER

All that has been said before about interrupts and interrupt sharing has a very simple explanation at the hardware level. In the beginning, the IBM PC had a poor interrupt hardware design:

Few interrupts, specially in the 8 bit PC (8 bit ISA bus).

Interrupts were not shareable at the hardware level. Being so, the operating system didn't support sharing interrupts.

The AT added some interrupts on the small connector on the 16 bit ISA bus, but they were still few and were not shareable.

The following is the original hardware on the IBM PC parallel port.B21 on the left is IRQ7; this signal comes from a buffer on U10 (74LS125) at the lower right (pins 11, 12 and 13).

Suppose you put two of this cards on ISA connectors on an old ISA PC (so B21 IRQ7 is common for both), and you enable its interrupts (pin 13 on U10 on both cards is low). While there are no interrupts from any card (pin 12 on U10 on both cards low) pin 11 on U10 on both cards will be low. They are shorted in B21 on the motherboard; this is not elegant, but still is not a problem. Now suppose one card interrupts, but not the other. It will try to raise its pin 11 on U10, while the other is holding it low. Disaster. So basically, if you try to share interrupts on the ISA bus you will violate TTL rules. If connecting ISA interrupt lines you must be sure that only one interrupt is active (for the previous example make sure that only one card uses interrupts).

Some brave people could try to cut traces on the motherboard and add diodes and resistors, or add an OR gate, but then there would come the other limitation: the operating system may not include the necessary code to share interrupts (basically, when a shared interrupt is generated make sure that all devices which may cause that interrupt are attended).

PC Card cards have many common characteristics with the 8 bit ISA bus. This explains many of the limitations which have appeared on all that has been said before.

As time passed, the PCI bus appeared, which allowed sharing interrupts at the hardware level, so operating systems (Windows, Linux, etc) supported it.

Therefore, above, when having two PC Card cards using ISA interrupts, they have to be carefully assigned so that they are different, and also different from other ISA interrupts used. However, this limitation does not appear in Cardbus cards and PCI devices, since they use PCI interrupts that can be shared at the hardware level, and the operating systems (Windows, Linux, etc) support it.

We consider the PCMCIA slot in our three Dell Latitude E5520 recently purchased (may 2011) laptops to be deffective mainly because of the following reasons:

PCMCIA slot with different behaviour on the three made in China Dell Latitude E5520 laptops. What about testing in Dell laptops made in China?

PC Card type cards are not recognized in all three (a previous conclusion is that Windows 7 still supports this type of cards).

Problems appear booting in Linux (pendrive or live CD): error messages are generated when inserting or removing cards ('dmesg').

In particular our Allen-Bradley communication card 1784-PCMK works differently on the three laptops:

E5520-L: works.

E5520-M: freezes.

E5520-N: resources problem.

Since there have appeared posts in other phorums asking if this card Allen-Bradley communication card 1784-PCMK is supported in Windows 7 here I include screen captures (on laptop named E5520-L above) on it, showing its resources and driver:(incluir E5520-L_1784_PCMK.png)

It itself downloaded its driver updating from Internet automatically.

CONCLUSIONS

We looked for a laptop with PCMCIA slot, and Dell offered it in the Dell Latitude E5520, and we hoped it would work. This has not been the case, and we are extremely angry and dissappointed. The three repair attempts by Dell have been useless, and more: Dell service for Spain has substituted without any reason the Windows 7 32 bits operating system in one laptop for the 64 bits one, which not only is useless for us (we use some industrial software which needs 32 bits Windows): they deleted our long Windows upgrades, our installed programs and our documents. This laptop is as usefull as a brick for us now, and Dell service for Spain (in Romania), not only doesn't help at all about the PCMCIA problem (they tell us to accept the laptop with this deffect), but also doesn't respond about the operating system substitution, no matter how many times we call them.

Windows XP and Windows 7 support PC Card and Cardbus cards. We purchased three Dell Latitude E5520 laptops with Windows 7 32 bits and claim PC Card and Cardbus cards to be supported.

The most important card for us (Allen-Bradley communication card 1784-PCMK) works different in the three laptops: freezes one (named above E5520-M), is not recognized by other (named above E5520-N) and works in other (named above E5520-L), which makes one wonder about China manufactured Dell laptops testing.

In spite that in one laptop (named E5520-L above) the most important card for us (Allen-Bradley communication card 1784-PCMK) works, we don't consider that its PCMCIA slot works, since other known to work cardbus cards don't work in it (apart from the PC Card type ones which as has been shown are still supported in Windows 7).

In spite of all considerations above about Windows XP and Windows 7 working or not with PC Card and Cardbus cards, in spite of all considerations above about PC card cards and Cardbus cards essentially disappearing from market, in our three deffective made in China Dell Latitude E5520 recently (may 2011) purchased laptops the PCMCIA problem is a hardware or bios problem, since booting in Linux (pendrive or live CD) error messages are generated when inserting or removing cards ('dmesg'). We keep waiting an answer from Dell to this.

Plug and Play configuration of resources for the following system components

Industry Standard Architecture (ISA) bus and devices

Serial ports and devices IEEE 1284­based parallel ports and devices

Under
Windows 95/98 (but not Windows NT® 4.0 or Windows 2000, XP, VISTA, Windows7), an ISA
device and its driver can support IRQ sharing if resource requirements
cannot be met. This capability applies only for devices of the same
class, not across device classes.

To share
IRQs, the following requirements must be met:

The IRQ line must be pulled high by the system
board.

The IRQ line must never be driven high by the
devices.

To signal an interrupt, devices must pull the
IRQ line low for a minimum of 100 nanoseconds and then release it. The
interrupt is signaled by the rising edge that occurs as a result of the pull-up
on the IRQ line.

The drivers for all devices connected to the IRQ
line must correctly support the interrupt-sharing services of the virtual
programmable interrupt controller device (VpicD). This means that after
dispatching an interrupt from VpicD, the drivers must respond to VpicD and
correctly indicate whether they actually processed an interrupt for their
devices. VpicD will ensure that all devices with pending interrupts have been
serviced before returning from the interrupt.

IRQ sharing support implemented in the device
driver for servicing interrupts.

Report Unresolved Customer Service Issues hereI do not work for Dell. I too am a user. The forum is primarily user to user, with Dell employees moderating.

Since there
have appeared posts in other phorums asking if this card Allen-Bradley
communication card 1784-PCMK is supported in Windows 7 here I include screen
captures (on laptop named E5520-L above) on it, showing its resources and
driver:(incluir
E5520-L_1784_PCMK.png)

This refers to the Allen-Bradley communication card 1784-PCMK, working in one
of our three deffective Dell Latitude E5520 recently purchased (may
2011) laptops, named E5520-L above. Some people have asked if this card was
supported in Windows 7. I had to leave, so I had no time to include figure
E5520-L_1784_PCMK.png, which includes screen captures on this board, showing its
resources and driver. Note driver date (january 25 2010). Here it goes:

When describing resources on a XP SP3 laptop with two PCMCIA slots and
a PC
CARD and a Cardbus cards inserted:

Compact Flash adaptor (with a CF card);

Parallel port (Moschip);

I
wrote:

They
appear as a PCMCIA IDE/ATAPI controller (with ISA IRQ4) and a PCI Parallel Por (LPT3) (with PCI
IRQ10), and also coexist peacefully. IRQ10 is shared by a lot of
devices.

IRQ4 should be IRQ7, as appears in the figure. ISA IRQ4 is occupied by COM1
communication port, and cannot be shared.

SpeedStep says:

I
have no Idea what VISTA or Windows 7 does but I suspect that the 16 BIT DOS ISA
IRQ's are not supported.

On
above tests
of PC Card cards and Cardbus cards using a PCMCIA to PCI adapter based on a
Ricoh RL5C475A chip inserted in a modern desktop with Windows 7 64 bits, low
numbered IRQ's are indicated as ISA. When the 56k modem PC Card card is
inserted, its IRQ is numbered as 0x10 (16), one unit above classical ISA interrupts (0-15). Go figure.

All I can say is that it worked perfectly (see above Teraterm session).

While above posts were written, on july 28 2011 Dell released a new bios for the Dell Latitude E5520 (version A02). On its features nothing is said about its PCMCIA slot problems, but it seems that this bios A02 solves them.

Resources for following cards:

Allen-Bradley communication card 1784-PCMK (Cardbus),

Parallel port (Moschip) (Cardbus),

Serial port (Oxford Semiconductor) (Cardbus),

Compact Flash adaptor (with a CF card) (PC Card).,

USB 2.0 adapter (NEC) (Cardbus),

follow:

We have succesfully upgraded to bios A02 two of the three laptops (named E5520-L and E5520-N above) and PCMCIA cards work satisfactorily, with resources shown above. Third laptop (named E5520-M above), which froze when inserting any Cardbus card, will be tested in two weeks.

No one from Dell Service for Spain (in Romania), after one and a half month since problem was detected (mid june), told us to wait for a next coming bios. In adition, someone, graciously illuminated, for solving a bios problem, as we had anticipated, substituted in named above E5520-N Dell Latitude E5520 its Windows 7 32 bits operating system for the 64 bits one, deleting our long Windows upgrades, our installed programs and our documents, and leaving the laptop as usefull as a brick for us, since we use some industrial software which needs 32 bits Windows.

So people owning a Dell Latitude E5520 laptop should upgrade its bios to version A02. Finally, it is an excellent laptop, with an excellent screen (we purchased the one with 1920x1080 screen).

Tarantulito - Would you be so kind as to share the exact configuration of your laptops? I am also looking at purchasing new laptops for our company and am concerned about functionality with Rockwell's PCMK and Windows 7.

If you have successfully configured a laptop to do this I would very much appreciate knowing the details.

We didn't do any test in 64 bits while we had the 64 bits operating system which erroneously Dell substituted in one of our Dell Latitude E5520 laptops (the one named E5520-N above).

We had a communication from Rockwell before the laptop purchase thet their software wasn't supported in 64 bits at that moment, so we went on with 32 bits, even this supposed the 4GB limit (actually less).

No experience in VMware.

Get a PCMCIA to PCI adapter and do the tests you want in a desktop. They are very cheap. Se above tests wit one based on a Ricoh RL5C475A chip in a modern desktop with Windows 7 64 bits.

On my E5520's the PCMCIA cage was messed. It was missing the Polyimide Film Tape that separated the pins from the conductor that they lay on. They sent me new cages with tape, and I tested the old cages with some different tape just to check if I was right.